NEUROIMAGING IN HIV-INFECTION - A PRELIMINARY QUANTITATIVE MRI STUDY AND REVIEW OF THE LITERATURE

A review of both functional and structural imaging of the brain throug h the course of HIV infection leads to a fairly consistent pattern of involvement. Brain involvement in asymptomatic HIV positive individual s remains controversial. However, in symptomatic subjects. less contro versy exists. Subcortical structures appear to be vulnerable early, fo llowed by cortical and eventual diffuse involvement. Specific abnormal findings include symmetrical atrophy, hyperintense white matter lesio ns, both subcortical and cortical ventricular enlargement and focal me tabolic abnormalities. It has not been possible to correlate the speci fic underlying pathological mechanisms responsible for each of these l esions and the pathophysiology probably involves multiple mechanisms, both direct and indirect. Some of these lesions are reversible with tr eatment, but the full implications of this reversibility with regard t o pathogenesis and prognosis remain speculative. New evidence presente d here suggests that both gray and white matter are involved in the at rophy.